1. Field of the Invention
This invention relates to system for conditioning a sample for introduction into a sample analysis system and more particularly a system which conditions a sample for introduction into a sample analysis system such as an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) or an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES).
2. Description of the Prior Art
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) are two common analytical techniques used by laboratories for the determination of trace element concentrations in liquid samples. The ICP is an electromagnetically generated partially ionized argon plasma which a temperature of approximately 7000K. When a sample is introduced to the ICP, the high temperature causes sample atoms to become ionized or emit light. Since each chemical element produces a characteristic mass or emission spectrum, measuring said spectra allows the determination of the elemental composition of the original sample.
In normal operation, a liquid sample must first be dispersed into an aerosol prior to measurement using an ICPMS or ICPAES instrument. Typically, a polydisperse aerosol is created utilizing a nebulizer. The aerosol is then sorted in a spray chamber to remove the larger aerosol particles. Other processes such as aerosol agglomeration which causes larger droplets to form from smaller ones may also occur inside the spray chamber. Upon leaving the spray chamber, the aerosol is introduced to the ICPMS or ICPAES via a tubular injector. Transport efficiency of the nebulized sample out of the spray chamber may typically range from only 20% down to 2%, depending upon the type of nebulizer employed, the quality of aerosol produced by the nebulizer, and the sample liquid flow rate. This means that typically the majority of the sample goes to waste, reducing the potential intensity of the analytical signal.